Skeletal system forms the overall framework of human body and other animals. It is the scaffold over and around which various body parts are built or anchored. Besides this crucial function, skeletal system has several other functions too.
Conduction of impulses (C) is a function of nervous system or neural tissue. Therefore, this option is incorrect.
The adult human body has 206 bones and it comprises the Skeletal system that supports the body (A). The bone marrow synthesizes blood or carries out hemopoiesis (B). Further, it provides protection to soft organs (D). Besides these, the skeletal system also helps in calcium storage and endocrine regulation.
Therefore, options A, B and D are correct.